• by 3-5 months of age, all hemizygous mutant males exhibit abnormal electrical activity in skeletal muscle indicative of both myopathic and neurogenic changes, as shown by needle electromyography

• abnormal insertional activity occurs more frequently in the levator ani/bulbocavernosus muscles than in hind-limb muscles of mutant males and is absent in either muscle group of wild-type males

• abnormal spontaneous activity indicative of denervation occurs in all mutant males in both the levator ani/bulbocavernosus and hind-limb muscles, and consists of sustained and unsustained regularly firing positive waves occurring at a low frequency (<30 Hz)

• abnormal spontaneous activity occurs more frequently in levator ani/bulbocavernosus muscles (~50% of needle insertions) than in hind-limb muscles (~25% of needle insertions) and is not observed in wild-type muscles

• hemizygous mutant males develop androgen- and and glutamine length-dependent neuromuscular weakness associated with early myopathic and neurogenic skeletal muscle pathology and late development of neuronal intranuclear inclusions in spinal neurons